The inventive concept relates generally to semiconductor memory devices and memory systems. More particularly, the inventive concept relates nonvolatile memory devices incorporating a voltage supply controller.
Semiconductor memory devices may be respectively categorized as nonvolatile or volatile in nature according to their ability, or lack of ability, to retain stored data in the absence of applied power. The operation (e.g., program, read and/or erase) of nonvolatile memory devices requires the timed application of various control signals to the word lines, bit lines, and/or the semiconductor bulk of the constituent memory cell array. Certain control signals are termed “high voltage”. That is, certain control signals have a level higher than the level of a nominal power supply voltage applied to (or generated within) the nonvolatile memory device. For example, one or more high voltage signal(s) is typically applied to the memory cells of a memory cell array during a program operation and/or an erase operation. In this regard, some nonvolatile memory devices incorporate a high voltage generator that internally generates one or more of the required high voltage signals.